Sinker operating control for circular knitting machines



March 12, 1968 H.-IMBODEN ETAL SINKER OPERATING CONTROL FOR CIRCULAR KNITTING MACHINES Filed May 14, 1965 s Sheets-Sheefll March 12, 1968 I w. H. IMBODEN ETAL 2 SINKER OPERATING CONTROL FOR CIRCULAR KNITTING MACHINES Filed May 14, 1965 's Sheets-Sheet 2 March 12, 1968 w. H. IMBODEN ETAL 3,372,562

SINKER OPERATING CONTROL FOR CIRCULAR KNITTING MACHINES 3 Sheets-Sheet 5 Filed May 14, 1965 United States Patent Oflice 3,372,562 Patented Mar. 12, 1968 3,372,562 SINKER OPERATING CONTROL FOR CIRCULAR KNITTING MACHINES Walter H. Imboden, Midvale Manor, Reading, Richard M. Janda, Crestwood, Reading, and James H. Boyer, Jr., Mount Penn, Reading, Pa., assiguors to Textile Machine Works, Wyomissing, Pa., a corporation of Pennsylvania Continuation-impart of application Ser. No. 418,460, Dec. 15, 1964. This application May 14, 1965, Ser. No. 455,776

6 Claims. (Cl. 66108) ABSTRACT OF THE DISCLOSURE This machine will knit alternating courses of long and short stitches of a tuck pattern in the heel and/ or toe of a stocking and can also form consecutive courses of the same length in such recipr-ocatorily knit areas. A pivoted means when in one position stops sinker cap rotation during each forward stroke to yield normal length stitches and when in a second position stops sinker cap rotation during each reverse stroke to cause behind the neb knitting and thus long stitches. When the pivoted means is in the second position the usual bumper screw and post meet during each forward stroke to yield short stitches.

This invention relates to circular knitting machines adapted for both rotary and reciprocatory operation to knit tubular fabrics such as ladies stockings and more particularly to improved means for operating the needles and sinkers of the machines during reciprocatory operation of the machines to form heel and toe portions of the stockings with courses of plain stitches of the same length or to form such heel and toe portions with alternate courses of stitches of different lengths.

The present application is a continuation-in-part of our application Ser. No. 418,460, filed Dec. 15, 1964, as to all subject matter common thereto. Said application is directed to a multistation circular knitting machine and more particularly to means for controlling the operation of the needles at the main station of the machine during reciprocatory operation to form alternate courses of long and short stitches in the heel and toe portions of ladies stockings knitted on the machine with each pair of courses, comprising one of long stitches and one of short stitches, and also having a pattern of design stitches when desired.

It is an object of the invention to provide means in a circular knitting machine for forming design stitch patterns in ladies hosiery during both rotary and reciprocatory operation of the machine.

Another object of the invention is the provision of means in a multistation circular knitting machine for controlling the operation of the needles and sinkers to form design stitch patterns at the stations during rotary operation of the machine and for controlling the operation of the needles and sinkers to form design stitch patterns at one of the stations during reciprocatory operation of the machine.

A further object is the provision of means in a circular knitting machine having a main knitting station and at least one auxiliary station which means is adapted to control the operation of the needles and sinkers to knit plain stitch courses with stitches of the same length at both the main and auxiliary stations during rotary operation of the machine, and at one of the stations during reciprocatory operation of the machine, or to control the operation of the needles and sinkers to knit courses of stitches of different lengths at the main and auxiliary stations during rotary operation of the machine to form design stitch patterns, or to control the operation of the needles and sinkers to knit courses of stitches of different lengths at the main station in opposite directions during reciprocatory opera tion of the machine to form design stitch patterns.

Another object of the invention is the provision of a method of operating a multistation circular knitting machine having a needle cylinder and means for operating the sinkers and needles to form partial courses of stitches during forward and reverse strokes of the cylinder at one station, operating the sinkers and the group of needles in a first predetermined time relation and forming courses of plain stitches of one length during forward strokes of the cylinder at the one station, dividing the group of needles during the forward strokes of the cylinder following formation of the partial courses in the forward strokes to raise certain of the group of needles to a high path while retaining the other needles in a low path, and operating the sinkers and group of needles in a second predetermined timed relation at the one station during reverse strokes of the cylinder and forming stitches of a different length, the needles in the high path forming plain stitches and the needles in the low path forming design stitches.

With these and'other objects in view which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings the invention resides in the novel featuers of construction and cooperation-of parts as hereinafter more particularly pointed out in the claims.

In the drawings:

FIG. 1 is a plain view of a portion of a multistation circular knitting machine having control means according to the invention for the sinker mechanism of the machine;

FIG. 2 is an elevational view taken in the direction of the arrows 2-2 of FIG. 1;

FIG. 3 is a view taken in the direction of the arrows 3-3 of FIG. 2;

FIGS. 4, 5 and 6 are views on an enlarged scale illustrating the relative positions of the needles and sinkers at different stages during the formation of fabric stitches on the machine;

FIG. 7 is a developed view of the needle operating cams and jack selecting means of the machine a s' viewed when looking outwardly from the interior of theneedle cylinder, parts shown in dotted outline indicating nonoperating parts and those in full line indicating operat ing parts as during a reciprocatory operation of the cylin der in a forward or counterclockwise direction; and

FIG. 8 is a view similar to FIG. 7 but illustrating the parts as during reciprocatory operation of the cylinder in a reverse or clockwise direction.

Referring to FIGS. 1, 7 and 8 of the drawings there is shown a circular knitting machine basically of common type having a circle'of pivoted latch needles 10 which are mounted in slots in a cylinder 11 adapted for both rotary and reciprocatory operation, and main and auxiliary knitting stations indicated generally at 12 and 15, respectively. Station 12 is provided with yarn fingers 16 for feeding yarns to the needles 10 and cams for operating on butts 17 of the needles including a forward stitch cam 20 having a lower stitch drawing point 21 acting on the needles in rotary and forward movements of reciprocation of the needles, indicated by the arrow in FIG. 7, and a reverse stitch cam 22 having 'a lower stitch drawing point 23 which is at the same level as point 21 on cam 20. The reverse stitch cam 22 is retractable in a usual manner from an active position, in which it acts to clear the needles during plain knitting in the rotary direction -(the direction indicated by the arrow in FIG. 7) and the needles to form design stitch patterns in the stocking fabrics. Also provided at the main station 12 is a center cam 25, an upthrow cam 26 associated with the forward stitch cam 20 for raising the needles following stitch drawing movements in the forward direction, an upthrow cam 27 associated with the reverse stitch cam 22 for raising the needles following stitch drawing in the reverse direction, a guard cam 30, and a center or needle leveling cam 31 intermediate the forward and reverse stitch cams. Associated with the stitch cams 20 and 22 are conventional up or narrowing picks 32 and 33, respectively, and a down or widening pick 35 which operate on the needles in a usual manner during fashioning of heel and toe portions of the stocking fabrics knitted on the machine. Also associated with station 12 is a cam 36 for raising needles to be inactivated to a high inactive level prior to knitting the heel and toe, a cam 37 for lowering the needles selected to knit the toe while the remaining needles are being raised to a high inactive level by the cam 36 and a cam 40 for again lowering the high inactive needles to knitting position following formation of the heel and toe. The earns 36 and 40 are mounted for radial movement between active and inactive positions and the cam 37 is pivotally mounted for movement between active and inactive positions in a common manner.

Auxiliary station 15 is provided with yarn fingers 41 for feeding yarn to the needles and cams for operating on the butts of the needles only during rotary movements thereof including a forward stitch cam 42, an upper center cam 45 and an upthrow cam 46 for raising the needles following stitch drawing movements in the forward direction. The stitch cam 42 and center cam 45 are radially retractable to inactive positions to inactivate station 15 during reciprocatory knitting of the heel and toe at the main station in a common manner.

The forward stitch cam 20 at station 12 has a fixed upper portion'47 and a movable lower portion 50. The left end of the fixed upper portion 47 is extended upwardly and toward the left from the stitch drawing surface of the cam to form a point 49 lying above the butts 17 of the needles after being raised by cam 26. The lower portion 50 of cam 20 is adapted to be moved between a full-in position in which it acts on the butts of all of the needles and a partially retracted position in which it acts on the butts of certain ones of a special group of needles while missing the other needles of the group for locking the ends of yarns at station 15 when it is activated and inactivated generally in the manner set forth in British Patent No. 895,672, published May 2, 1962. The lower portion 50 of the cam 20 is also adapted to be moved to a fully retracted position to miss the butts of the needles for purposes hereinafter set forth. The means for moving the lower portion 50 of the stitch cam between its active and its partially and fully retracted positions forms no part of the instant invention and is shown in detail and fully described in said application Serial No. 418,460.

Cooperating with the needles 10 in forming courses of stitches at stations 12 and 15 are sinkers 51 (FIGS. 4, and 6) each of which has a neb 52, a knockover surface or platform 55 in front of the neb, a horizontal ledge 56 in back of the neb which is slightly higher than the platform for purposes hereinafter set forth, and a butt 57. As is common, the sinkers 51 are mounted for movement in the spaces between the needles in radially extending slots in inner and outer sinker rings (not shown) secured to the upper end of the cylinder 11 for rotation therewith and the sinkers are operated through their move ments in timed relation to the needles by a cam track 60 formed in a sinker cap 61 (FIG. 1) which acts on the butts 57 of the sinkers in a manner hereinafter set forth.

During plain knitting at the main and auxiliary stations with the cylinder rotating in the forward direction, indicated by the arrow in FIG. 7, the needles approach the main station 12 along a low path 62, commonly referred to as the tucking path or level, then rise over the reverse stitch cam 22 which is in active position at this time to a stitch clearing level 65 to clear the previously formed stitches on the needles below the latches thereof. At this time the sinkers are held in their inner positions by a garter spring (not shown) to hold the previously formed stitches on the needles as the needles rise. As the needles continue along the level 65 the sinkers are retracted by a cam surface 66 and the needles are lowered by cam 25 to take yarn at station 12. The needles are then lowered by the upper portion 47 and the lower portion 50, which is in full-in active position at this time, of the forward stitch cam 20 to draw new stitches over the platforms 55 of the sinkers. As the needles approach the lowest point 21 of the stitch cam 20 the sinkers are moved inwardly by a cam surface 67 to place the nebs thereof over the new stitches and to knock over the previously formed stitches on the needles. After passing the lowest point of the cam 20 the needles are again raised to the tuck level 62 by the cam 26 and at this time the sinkers remain in their inner positions to hold the new stitches. During continued movement of the cylinder in the forward direction all of the needles as they approach auxiliary station 15 are raised to a clearing level 70 to clear the previously formed stitches thereon by means, hereinafter set forth, and the needles are then lowered by the cam 45 which is in active position at this time to take the yarn of a finger 41 at station 15. At this time the sinkers are also retracted by a cam 71 forming part of the cam track 60. The needles are then lowered by the stitch cam 42 which is also in active position to draw new stitches over the platforms 55 of the sinkers. As the needles approach the lowest point of the cam 42, the sinkers are moved inwardly by a cam surface 72 of the track 60 to place the nebs of the sinkers over the new stitches and to knock over the previously formed stitches on the needles. After passing the lowest point of the cam 42 the needles are raised to the tuck level by cam 46 and at this time the sinkers remain in their inner positions to hold the new stitches. The cam 71 is carried on a slide 73 which is mounted for radial movement to move the cam between an active position in which it acts to retract the sinkers as above set forth and an inactive position, which is the position shown in FIG. 1, in which the cam does not act on the sinkers for purpose hereinafter set forth.

Conventionally during reverse reciprocatory strokes of the cylinder 11 at the main station 12 to form the heel and toe portions of stocking fabrics, the sinkers are retracted by the cam surface 66 in forward strokes of the cylinder prior to the operation of the needles by the stitch cam 20 to form a course of stitches and the sinkers are then moved inwardly by the cam surface 67 to hold the new stitches as the needles rise following stitch drawing as above set forth. In reverse strokes of the cylinder the sinkers are retracted by a cam surface 68 prior to the operation of the needles 10 by the reverse stitch cam 22 to form a new course of stitches and the sinkers are then moved inwardly by a cam surface 69 to hold the new stitches as the needles rise following stitch drawing.

The sinker cap 61 is mounted on the outer sinker ring for frictional movement with the cylinder to an extent permitted by a first stop member mounted in fixed position on the machine frame and by a third bumper screw or member 10']. and a first bumper screw or member 102 adjustably carried in projections 103 and 104, respectively, on the sinker cap to determine the lead of the sinkers over the needles at the time of stitch drawing movement of the needles. The bumper screws are held in adjusted position by lock nuts 105. During rotary operation and forward reciprocatory strokes of the cylinder the sinker cap is rotated with the cylinder until the bumper screw 101 engages the stop member 100 to position the cam surface 67 to time the inward movements of the sinkers in relationship to the stitch drawing movements of the needles and in reverse strokes of the cylinder the bumper screw 102 engages the stop member to position the cam surface 69 to time the inward movement of the sinkers in relationship to the stitch drawing movements of the needles. Normally this relationship of the sinkers and needles is such that when the head of each needle is lowered by the stitch cam 20 to a position in which it is level with the platforms of the sinkers, approximately the fourth sinker leading the needle, when considered in the forward direction, is moved inwardly to its fullest extent by the cam surface 67. Likewise, when the head of each needle is lowered by the reverse stitch cam 22 to the position in which it is level with the platforms of the sinkers, approximately the fourth sinker leading the needle, when considered in the reverse or clockwise direction, is moved inwardly to its fullest extent by the cam surface 69'. Generally this relationship of the sinkers and needles is termed the normal lead of the sinkers over the needles and is such that as each needle reaches its lowest stitch drawing position the sinkers adjacent thereto have extended the yarn to the back of the needle as shown in FIG. 4 and actually assists in determining the length of the stitches drawn by the needle.

The means for raising the needles to latch clearing level 70 at the auxiliary station includes pattern jacks 75 (FIGS. 7 and 8) which are of the rocking type and which act through intermediate jacks 76, there being a pattern jack and an intermediate jack in the slots in the cylinder for each needle 10. Each jack 75 has a lower butt 77 adapted for engagement with a raising cam 80 at the auxiliary station 15 when the lower ends of the jacks are rocked outwardly through engagement of a presser cam 81 with upper portions 82 of the jacks. The presser cam 81 is moved between inactive and active position to act on the jacks in a common manner. Following a raising movement of the jacks 75, jacks 76 and needles 10 by the cam 80 at the auxiliary station the jacks are again returned to their lowermost positions by a cam surface 85 which acts on butts 86 on the jacks 76.

The pattern jacks 75 are also adapted to be controlled so that only selected ones of the jacks are raised by the cam 80 at the auxiliary station to raise their associated needles to the latch clearing level 70 while the other needles remain at the tucking level 62 determined by the cam 26, for purposes of forming design stitch patterns in the stocking fabrics. For so selecting the jacks 75 they are provided with usual breakable pattern butts 87 at a plurality of levels which are adapted to be engaged by selector levers 90 to again move the lugs 77 out of the path of the cam 80 after the jacks have been necked outwardly by the presser cam 81. Thus the jacks on which the butts 87 are unbroken are acted on by the selector levers 90 while those jacks having their butts removed are raised by the cam 89 to move their associated needles to clearing level. The selector levers 90 are operated by selecting means including a trick drum (not shown) when in active positions and are adapted to be moved both individually and in groups between their active and inactive positions in a common manner.

The needles 10 may also be selectively controlled at station 12 through the jacks 75 and 76 in the same manner as at station 15 for the purpose of forming design stitch formations in the courses formed at station 12. The means for this purpose includes a raising cam 91, similar to cam 80, for raising the jacks 75, a presser cam 92 acting on the upper portions 82 of the jacks, a cam surface 95 acting on the butts 86 of the jacks 76 for lowering these jacks and the jacks 75 raised by the raising cam 91, and selector levers 96 which are operated by a trick drum (not shown) when in active position in the same manner and for the same purpose as selector levers 90 as above set forth.

Conventionally in forming a stocking fabric on the machine it is operated in a rotary or run-down manner to form a turned Welt, after-welt, leg and foot portions of the stocking and the machine is operated in a reciprocatory manner to form the heel and toe portions of the stocking. To form plain stitch fabric in the rotary knit portions, yarns are fed at each of the stations 12 and 15 and movements of the needles are controlled at the main station 12 by the needle operating cams and at the auxiliary station 15 by both the needle operating cams which are in active positions at this time, and the jacks 75 in the manner hereinbefore set forth. Where it is desired to form a pattern of tuck stitches in one of the rotary knit portions, the appropriate selector levers are activated at one of the stations to act on the jacks 75 to determine the needles that are to be operated to form plain stitches and the needles that are to form the tuck stitches. The needles at the other station are controlled to form courses of plain stitches. When the auxiliary station is set up to form the tuck stitch courses, a plain course is first formed at the main station 12 and the jack selecting means at station 15 is activated to control the selection of the needles to form the tuck stitch pattern. When the main station 12 is arranged to form the tuck stitch courses, plain courses are first formed at the auxiliary station and the jack selecting means at station 12 is activated to control the selection of the needles to form the tuck stitch pattern and the reverse stitch cam 22 at station 12 is in retracted position at this time to permit the needles selected to form the tuck stitches to remain at the tuck level as they pass cam 22.

Where it is desired to provide the tuck stitch pattern with nonrun or run-resist characteristics, courses of short plain stitches are knit at one of the stations and courses of long stitches are knit at the other station during each rotation of the cylinder with selected short stitches of the first course being held and tucked with long stitches of the second course to form the tuck stitch pattern. For this purpose the main station 12 is arranged to form the courses of short stitches. At auxiliary station 15 the appropriate selector levers 590 are activated to operate the jacks 75 to control the needles that are to form the tuck stitch pattern and the slide 73 is operated to move the sinker cam 71 to inactive position so that the sinkers will remain in their inner positions as they pass through station 15. Thereafter during each rotation of the cylinder 11, the sinkers are retracted by the cam surface 66 at the main station 12, all of the needles are lowered by the stitch cam 20 to draw stitches of the yarn of station 12 over the platforms 55 of the sinkers to form a course of short stitches and the sinkers are then moved inwardly by the cam surface 67 to knock over the previously formed stitches on the needles and to hold the new stitches as the needles are again raised to the tucking level. At the auxiliary station selector levers determine the needles that are to be raised to clearing level by the jacks 75 to form plain stitches and the needles that are to remain at the tucking level to form the tuck stitches. All of the needles then take yarn at the station 15 and draw stiches over the high ledges 56 in back of the nebs 52 of the sinkers 51 (FIG. 6) to form the plain and tuck stiches of the long stitch course.

According to application Ser. No. 418,460 means were also provided to form a tuck stitch pattern in the reciprocatorily knit heel and toe portions of the stockings at the main station of the machine, this means being operative irrespective of the type of stitch formation produced in the rotary knit portions of the stockings. As set forth in said application, for so forming the tuck stitch pattern in the heel and toe a group of selector levers of the jack selecting means associated with the auxiliary station is arranged to act on the jacks during forward reciprocatory strokes of the cylinder. The selector levers are moved from inactive to active position to be acted on by the trick drum of the selecting means in the conventional manner and then are moved from active to inactive position during each reverse reciprocatory stroke of the cylinder. Also the lower portion of the forward stitch cam is moved to a fully retracted position during each reverse reciprocatory stroke of the cylinder. Following the formation of each course of the heel (or toe) during reciprocatory strokes'of the cylinder in the forward direction, the selector levers function to select the jacks that are to raise their needles to a clearing level and the needles that are to tuck remain in the tucking path to which they were raised by the upthrow cam associated with the forward stitch cam at the main station. Thereafter during the reverse stroke of the cylinder the needles in the cleared path pass over the forward stitch cam to form plain stitches and the needles in the tucking level are directed along a path beneath the cam to form the tuck stitches in the manner hereinafter set forth. The means for and the manner of moving the lower portion of the forward stitch cam and the group of selector levers and the needles to form the tuck stitch in the heel and toe are fully shown and described in said application Ser. No. 418,460.

Where the tuck stitch pattern in the heel and toe was only for the purpose of providing an ornamental effect, the lower points of the forward and reverse stitch cams are at the same level to form stitches of the same length in both the plain stitch courses drawn by the forward stitch cam and the tuck stitch courses drawn by the reverse stitch cam. However, when the tuck stitch pattern was to have both ornamental and nonrun characteristics the stitches in the plain courses were made shorter than the stitches in the tuck stitch courses. To obtain the plain stitch courses and the tuck stitch courses the forward stitch cam was retained in its normal vertical operating position to draw short length stitches while the reverse stitch cam was designed to draw the longer stitches of the tuck stitch courses. However, while this was satisfactory where both the heel and toe were to be provided with the nonrun tuck stitch pattern, Where only the heel was to be provided with the nonrun tuck stitch pattern and the toe was to be knit of all plain stitch courses, or vice versa, this procedure would result in the plain knit toe or heel as the case would be, having courses of long stitches alternating with courses of short stitches which was undesirable.

In order to permit the formation of either the alternating courses of long and short stitches of the tuck stitch pattern in the heel and/or toe of the stocking or to form plain courses with stitches of the same length during both directions of reciprocation at the main station 12, in accordance with the instant invention the forward and reverse stitch cams terminate at the same level and the control of stitch length is obtained by adjustment of the sinker cap. Thus the position of the sinker cap 61 is adjusted at times to provide the normal lead of the sinkers over the needles whereby plain courses of the same stitch length will be formed in both directions of knitting. At other times the sinker cap is adjusted to provide an abnormal lead of the sinkers over the needles to form the alternate plain courses of short stitches and the tuck courses of long stitches required in the reciprocatorily knit nonrun tuck stitch pattern. For positioning the sinker cap to provide the normal sinker lead over the needles, the bumper screw 102 is adjusted to cause the sinker cap, in the reverse reciprocatory strokes of movement of the sinkers and needles, to assume its usual position. The sinker cap is positioned to provide the normal sinker lead in the forward direction of knitting in both rotary operation of the sinkers and needles and in the forward reciprocatory strokes of the sinkers and needles by a second bumper screw or member 110 adjustably carried in a plate or support member 111 mounted in fixed position on the bumper screw 101 between the projection 103 and the lock nut 105 (FIG. 1). The bumper screw 110 is held in adjusted position in the plate by a lock nut 112 and is adapted to engage a second stop member comprising one arm 115 of a lever 116. The lever 116 is pivotally mounted on a stud 117 carried in fixed position on a bracket 120 secured to a portion of the stop member 100 by screws 121 (FIGS.

1, 2 and 3).

The lever 116 is adapted to be moved from an active position in which the arm is positioned for engagement 'by the bumper screw 110 to control the position of the sinker cap 61 during movement of the cylinder 11 in the forward direction and to an inactive position for purposes hereinafter set forth. For so moving the lever 116 to its active position a second arm 122 of the lever is connected by a Bowden Wire 125 or the like to a pattern lever 126 which is operated by cams 127 on a cam drum 130 of the machine. A spring 131 connected between the bracket 120 and arm 122 (FIGS. 1 and 2) normally tends to bias the lever 116 to its inactive position.

For positioning the sinker cap 61 to provide the abnormal sinker lead over the needles in forward strokes of reciprocation during the formation of the heel and toe, the position of the bumper screw 101 in the projection 103 is adjusted to delay the action of the cam surface 67 in moving the sinkers inwardly until the sinker lead over the needles is increased approximately six sinkers. With this sinker lead the inward movement of the sinkers in relationship to the stitch drawing movements of the needles is such that the length of the stitches is controlled entirely by the depth of movement of the needles in relationship to the platforms 55 of the sinkers 51, as shown in FIG. 5, which results in the formation of stitches which are shorter than those normally formed when the sinkers have the normal lead.

To obtain the courses of long stitches in reverse strokes of reciprocation of the cylinder the sinker cap is positioned to advance the action of the cam surface 69 so that the sinkers are moved inwardly prior to stitch drawing movements of the needles and the stitches are drawn over the higher ledges 56 in back of the nebs 52 of the sinkers, as shown in FIG. 6. For so positioning the sinker cap there is provided a fourth bumper screw or member 132 which is adjustably carried in a bracket 135 secured to the arm 115 of lever 116 by screws 136. The bumper screw 132, which is held in adjusted position by a lock nut 137, is adapted to engage plate 111 when the lever 116 is in inactive position to stop and position the sinker cap in its clockwise position during such reverse strokes of the cylinder.

During rotary knitting of plain stitch courses of the fabric at both the main and auxiliary stations 12 and 15, a cam 127 on the cam drum 130 is moved beneath the lever 126 to move the lever 116 to active position to cooperate with bumper screw 110 and position the sinker cap 61 to provide the normal sinker lead over the needles. The lever 116 is also in active position to provide the normal sinker lead over the needles where it is desired to form a tuck stitch pattern having runresisting characteristics. At this time the sinkers and needles are operated in their normal relationship at station 12 to form the courses of short stitches of the tuck stitch pattern. At station 15 the sinker cam 71 is moved to inactive position and the longer stitches of the tuck stitch course are formed over the ledges 56 in back of the nebs of the sinkers as hereinbefore set forth.

Where it is desired to form plain courses all of the same stitch length in the heel and toe at the main station 12 during reciprocatory operation of the machine, the lever 116 is moved to active position to control the position of the sinker cap to provide the normal sinker lead in forward strokes of reciprocation and the bumper screw 102 engages the stop member 100 to control the position of the sinker cap to provide the normal sinker lead in reverse strokes of reciprocation. At this time the sinker cam 71, and the needle operating cams 42 and 45 at station 15 are in inactive position. Also at this time in order to raise the needles knitting the heel (or toe) courses above the point 49 at the left end of the upper portion 47 of the cam 20, following a knitting stroke of the needles in the forward direction so that the needles will pass above the upper portion 47 during a knitting stroke in the reverse direction in the conventional manner, the presser cam 81 at the auxiliary station 15 is moved to active position to cause the jacks to raise the needles to the clearing level 70 during each forward stroke of the cylinder. Thereafter as the cylinder is reciprocated in the reverse direction the needles pass over the upper surface of the cam 20 and then are lowered by the reverse stitch cam 22 to knit in the usual manner.

Where the heel and toe is to be provided with a runresistant tuck stitch pattern, the lever 116 is moved to its inactive position, as shown in FIGS. 1 and 3, a group of selector levers 90 associated with auxiliary station 15 is activated to select the needles forming the tuck stitch pattern and the means for alternately moving the selector levers and the lower portion 50 of the cam 20 between active and inactive position is activated. Thereafter during each forward stroke of reciprocation of the cylinder the sinker cap is moved to its position as determined by engagement of the bumper screw 101 with the stop member 100 to retard the inward movement of the sinkers, and the needles knitting the heel (or toe) courses are then lowered by the forward stitch cam 20 to form a course of short stitches over the platforms of the retarded sinkers in the manner above set forth. Following the stitch drawing movement of the needles by the cam 20 and while the cylinder continues to move in the forward direction the sinkers are moved inwardly by the cam surface 67 to hold the new stitches as the needles are raised to tuck level 62 by the cam 26. The selector levers then act on the jacks to select the needles that are to remain at the tuck level 62 and the other jacks are raised by the cam 80 to raise their needles to the clearing level 70. Prior to the reverse stroke of the cylinder the group of selector levers 90 are moved to inactive position and the lower portion 50 of the stitch cam 20 is moved to its fully retracted position. As the cylinder is moved in the reverse direction the sinker cap is moved with the cylinder until the plate 111 engages the bumper screw 132 to cause the cam surface 69 to advance the time of the inward movement of the sinkers. Thereafter during continued movement of the cylinder both the needles in the clearing level which pass above the upper portion 47 of the forward stitch cam 20 and the needles in the tucking level which pass beneath the upper portion 47 draw their stitches over the ledges 56 in back of the nebs 52 of the sinkers to form the alternate plain and tuck stitches of the long courses.

It will be understood that the improvements specifically shown and described 'by which the above results are obtained can be changed and modified in various Ways without departing from the invention herein disclosed and hereinafter claimed.

What is claimed is:

1. In a circular knitting machine having a main knitting station and at least one auxiliary knitting station,

(a) a cylinder adapted for both rotary and reciprocatory operation,

(b) needles in said cylinder,

(c) means for feeding yarns to said needles at each of said stations,

(d) cam means at said main station for operating said needles through stitch drawing movements to form courses of stitches thereat during rotary operation of said cylinder in a forward direction and during reciprocatory operation of said cylinder in opposite directions,

(e) cam means at said auxiliary station for operating said needles through stitch drawing movements only during rotary operation of said cylinder in said forward direction,

(f) sinkers cooperating with said needles in forming said courses of stitches at said stations, said sinkers 10 having a neb, a stitch drawing surface at one level in front of said neb, and a stitch drawing surface in back of said neb at a higher level than said stitch drawing surface in front of said neb,

(g) a sinker cap having cam means for moving said sinkers outwardly and for again moving said sinkers inwardly in timed relation to said stitch drawing movements of said needles at said needles at said main station during said rotary and reciprocatory operation of said cylinder,

(h) cam means in said sinker cap for moving said sinkers outwardly and for again moving said sinkers inwardly in timed relation to said stitch drawing movements of said needles at said auxilary station only during said rotary operation of said cylinder, said sinker cap being adapted to be rotated with said cylinder to move said cam means for said sinkers to predetermined positions in relationship to said needle operating cam means at said main and auxiliary stations during rotary and receprocatory operation of said cylinder,

(i) first means for determining rotated positions of said sinker cap and cam means for said sinkers at said main station during reciprocatory operation of said cylinder to operate said sinkers in timed relation to the stitch drawing movements of said needles whereby said needles draw courses of stitches of one length over said surfaces in front of said nebs of said sinkers in both directions of reciprocatory operation of said cylinder, and

(j) second means for determining rotated positions of said sinker cap and cam means for said sinkers at said main station during reciprocatory operation of said cylinder to operate said sinkers whereby said needles draw courses of stitches of a second length over said surfaces in front of said nebs of said sinkers in one direction of reciprocatory operation of said cylinder and said needles draw courses of stitches of a third length over said surfaces in back of said nebs in the other direction of reciprocatory operation of said cylinder.

2. A machine according to claim 1 in which said first means for positioning said sinker cap and cam means for said sinkers includes a first stop member, a first adjustable member associated with said sinker cap and cam means for engaging said first stop member to position said cam means in one direction of reciprocatory operation of said cylinder, 21 second stop member, a support member carried by said cam means, a second adjustable member in said support member for engaging said second stop member when in active position to position said sinker cap and cam means in the other direction of reciprocation of said cylinder, and means for moving said second stop means between active and inactive positions.

3. A machine according to claim 2 in which said second means for positioning said sinker cap and cam means for said sinkers includes a third adjustable member for engaging said first stop member when said second stop member is in inactive position to position said sinker cap and cam means in one direction of reciprocatory operation of said cylinder, and a fourth adjustable member for engaging said support member when said second stop member is in inactive position to position said sinker cap and cam means in the other direction of reciprocatory operation of said cylinder.

4. A machine according to claim 3 in which said fourth adjustable member is carried on said second stop member and said fourth adjustable member is positioned to engage said support member when said second stop member is moved to inactive position.

5. In a circular knitting machine having a knitting station,

(a) a cylinder adapted for both rotary and reciprocatory operation,

(b) needles in said cylinder,

(c) means for feeding yarn to said needles at said station,

((1) cam means at said station for operating said needles through drawing movements to form courses of stitches thereat during reciprocatory operation of said cylinder in opposite directions,

(e) sinkers cooperating with said needles in forming said courses of stitches at said station, said sinkers having a neb, a stitch drawing surface at one level in front of said neb, and a stitch drawing surface in back of said neb at a higher level than said stitch drawing in front of said neb,

(f) cam means for moving said sinkers outwardly and for again moving said sinkers inwardly in timed relation to the operation of said needles to form said courses of stitching during reciprocatory operation of said cylinder, said cam means for said sinkers being adapted to be rotated with said cylinder to predetermined positions in relationship to said needle operating cam means during rotary and reciprocatory operation of said cylinder,

(g) first means for determining rotated positions of said cam means for said sinkers during reciprocatory operation of said cylinder to operate said sinkers in timed relation to said needles whereby said needles draw stitches of one length over said surfaces in front of said nebs of said sinkers in both directions of reciprocatory operation of said cylinder,

(h) second means for determining a rotated position of said cam means for said sinkers to operate said 12 sinkers in one direction of reciprocatory operation of said cylinder whereby said needles draw stitches of a second length over said surfaces in front of said nebs of said sinkers, and

(i) third means for determining a rotated position of said cam means for said sinkers to operate said sinkers in the other direction of reciprocatory operation of said cylinder whereby said needles draw stitches of a third length over said surfaces in back of the nebs of said sinkers.

6. A machine according to claim 5 in which said second positioning means for said cam means for said sinkers in part includes said first positioning means and said third positioning means for said cam means in part includes said first position means.

References Cited WILLIAM CARTER REYNOLDS, Primary Examiner. 

